Electron discharge device



Sept. 21, 1948. Y 1 H, L STEELE, JR i 2,449,794

ELECTRON DISCHARGE DEVICE Filed Oct. 12, 1944 5 IIIIH lhl Q 4 F1 I mi i'llllllll lNvENoR A-675525, Ja

ATTORNE Patented Sept. 21, 1948 UNITED.; S'.'ATES` `(311:51:

2,449,794 ,Y l ELEo'rnoN DrsoHARGEfiinvion Howard L. Steele, Jr., Bloomfield, N.J., assigner,K4

to Westinghouse Electric Corporation, Eastr Pittsburgh, Pa.,- a .corporation offlennsylvania..l Applicationctober 12, 1944; Serial N o) 558,298

15 Claims. Clase-1927.5)

This invention relates to electron discharge -devices of the-character known as magnetrons, and

more particularly :to tuning means for the same.`

A recent development `in this art `:hastbeen termed crown of thorns as somewhat descrip-1 tive of a tuning means for -a magnetron, and consists ofA a plurality of metallic prongs, `one in each of several resonant cavities of 'a magnetron,- and carried from a movable support so the several `1O prongs maybe moved longitudinally and simul` taneously'in the cavities. Presence of metallic prongs of such a device raises the resonant 'fre-l fluencyA of the output from the normal frequency the device would have `withoutthe prongsorwith the prongs withdrawn, butprovides nomeans .for

lowering'the resonant frequency' toone below the normal frequency of the device. I

Broa-dly stated, then, an` object of 'the `present. invention is to provide a tuning means for a'magnetron Which-willaccomplish ytuning by a crown of thorns vconstruction `in -a wider range than."

accomplished by the known device.

Likewise of general nature, the invention contemplates tuning means,-which will tune to a fre-' quency lower than-the normal 'resonantfrequency' of the magnetron.

More in detail,` the inventionhas for an objectl to provide a movable tuningmeans within a mag-- netron whichlmay be tuned either to frequencies,l above or belownormal resonant frequency ofthe magnetron.

Another object of`\.the invention'is `to effect` progressive tuning or frequency change in either direction-from normal resonant frequency df `the magnetron;

Otherobjects` of the inventionjwill appear "t0 those skilled in *the f art Vas the Vdescription kprolgresses, both bydirect recitation thereofand byinference fromthe context.

Referringl to the accompanying"drawings in whichy likenumerals lof reference indicate similar parts throughout the several views; l

Figure -1 is `a plan with cover or lend plate ree moved of a magnetron constructed in accordance'.-

with and-showing the tuning means 0f the IJT'BSEIIGv invention;

Figure 2 is a sectional viewtaken on `lineIILII of Fig. 1, but with the cover or end plate in position ing ring-'supporting means; l.

Figure 3 is a detail sectionalview of apart of"` the magnetron as on `line III-"-III'of 1, show Figure 4 is a perspective View of the ring. and its associatedprongs and supporting means; l o

Figures 5rand6 are cross sectional -.views of'i modified constructions of magnetron cavities and showing l twomodified;` constructions ofV tuning..-

means therein; and

Figure l 'isa cross sectional view of magnetron into'one `01- 'the resonantcavities of the magne tron; and is shown `asin v'part` comprising ametallic portionwandvin part 'a :dielectric p ortionta'nd` eachportion lis at .leastin l part always .within` the cavity;1 While :the drawingshows one of thetun` ing elements fini' eachresonant cavity exceptV the onehavi-ngfthe. outputrlooptherein, it is within the 'scopewoffthea invention to utilize the tuning elements: in anyhumber: offv the resonant cavities de" sired fand fornrangeof :tuningzwhich the number-V employed awill i accomplisll;l t

Referring fnowt specifically to the embodiment of the invention illustratedin the severaliigures,`

the reference numeralf l''designates a cylindrical metallic zmagnetronfzbody the ends whereof "have coverror'iend plates II "sealedthereon that they interiorl may be evacuated. Withiniand as anintegralpart of said Vbody'is the usual magnetron" anode 'structurel I 2"'of generally cylindrical vsl'iape butshorter than the Aouter part ofthe body so as to 'provide endfspaces I 3 between the anodev and said end' plates I I: `The anode structure is axially hollowftorprovidela'cathode cavity for a cathode I 4 `and radi-ating: from" this cathodefcavity are t a L pluralityvof resonantvc'avities I geach having, in the `formsashowrrin Figures 1 to lindrcal portion. parallel .to .thecathode cavity.

nated segments.orivanesfl. The ends of the cathode cavity and the ends of said resonant' cavitiespinrall formsfshowmopen into the end vspaces IS... C'athodeJIII passesfaxiallyfthroughthe catli- Y '-ode cavityfadequately spaced from the anode; and

is supported'as usual `fro'rrrlead-'in rods II enter-A ing the end cavitiesattheisides thereof.` An outer putdoop: nI8 isls'ituated iinwone end space, passing outthroughthesidewall of the body portion.

lInWcarryingfout fthe present invention, the

tuning-rmeans includesl acrown, shown alone in Fig. .4,flsaid crownbeingfabricated-with a broken or partial ring. .|9;-'which may be either of metal `or tofs@insulatormaterial, "centered on an axisA "whichfinuses isi coaxial with thelaxisof the cath# l i 3 inclusive, a cy-` ode and anode of the magnetron. When the crown is assembled in the magnetron, said ring is within one aforementioned end space I3. Projecting from the ring, in parallelism to the said axis, are a plurality of metallic prongs 20 evenly 5 spaced in an annular series, except that there may be one prong omitted in the series corresponding tothe-cavity having the outputloo-p, but otherwise there is shown one prong on the ring for each resonant cavity l5 of the magnetron. The number of prongs employed, however, may be varied as desired. All of the prongs have the same relation to their respective resonant cavity walls or vanes at any given position of the crown, and movement axially of the {crown makes a corresponding change of position for all of said prongs with respect to the xedvanes. For instance, one position of the crown vanes is shown in solid lines in Fig. 2 andanother position thereof is shown by adjacent dotted lines. Furthermore, the prongszare. free of contactlfromthe'icy fi.. lindrica1 wall or the 1 magnetronbod asr well'fas from the cavity walls or vanes.

Thescrown hasfas afpartfthereoifa mount y which it :is .retained coaxial 1 andfin Figures? is shown J supported-:td beffmovable' orrslidableiax ial1y:.` SaidV mo'untigisi: illustranted:- as ,@'zprovidingffa crosse'bar.` or yoke :2 I"v 'diametricallyr-zacross: Sandi; -i securedto the-ring andrexten'dinger:therebeyondif where' fdepending. guide rods or .alegs'r22-iare. rrig.- 30"'` idly fattached. fiThefcross-bar'orsyokeez'l may. be.. metal :or-.insulative material, `aridfsaidfle'gs 22 may fr likewise-'beifinsulativerf. Asfeshowm Isaid,flegsfare constructed;l with `metal ycores.:having@insulating sleeves f; held' .there'on i-nr suitable mannenfv.vv Use fof 35Y such insulationfas :Well as., iuseiof insulatingfsm terial g for the ringsoand `yoke-:have xthetadvantagefthat they will .avoid settingu-p inductionfcurs rent-'iloW and. likewise:-will;.insure;that fthe oper;- ating` means des'cribedehereinbelowf may tbe-aat 4.0 ground; directvcurrent ,potentiala .fSaidsIegSa-:EZZ i slide in holes 23 1in-fthe magnetronzbody portion and not only prevent rotation-:.ofwtheicrowniiinfm Figs.v 1. to 4 `:butt-also; keepptl'ie"l ringv perpendicular to theaxis ofthernagnetronbody `order to ,slidablyad'ust thegcrownlfont ing ypurposes,-a lever :524' is f shownrasizjhaving" an inner forked end:each=-,tine of whichv is :bifurcated. for'engaging above and ,below'.` said .crossebar or yoke- 2 I ,.,isaid lever projecting in ai generally 50 radial direction fIOmj; engagement :with-*said r-,yoke to a distance outsidev 1 of the .magnetron-L .fbo'dy Said; lever, however,V -isf,enclosedfwithinea housing 25 Awlilich includes-atilexbleqportion 2 iibyi which vacuum sealing of ether,magnetron-finteriorriis 553 maintained butfgby which :said: leven-isV :permitted to pass` .tov theYexterior-and:beil there '.un'deri; con.- trolpf: the operator: Pivoting.sofylsaidialever elected f by.; af suitable .pivot fpin.A crosswiseliiof. .fa sawpfslit boss forming:part.ofi'saidh'ousirgfand 601?v locatedvwithin saidjflexible .portion 2-6;.. i

Inasmuch: 'asrsaid"` leverifZllr-mustsbe held e curely.` in adjusted eposition, retainin'gas .wellasfI adjusting means are Ipr,ovidecla-forthepurpse As ishoWl; the filever'., hasa.; head; 21. ethereonaat whichl .flexible housing @artcu 26. is secured andA alsogon whichrissecuredra,bra'cketfZlB .which prio vides aforked endlaterally;'ofitheleyerl vFA sleev 29 extending -in,.the;; same.y generalefvdirectionfa theflever. .Sf pivotally carried: by said forked-en 0f hlaket' so as toswing inthe; same .piangi whichthe lever swings:` 'liongitudinally throug the s leeve, and in threaded engagement there witltds an adjusting screwwsli navingfaebalnand socket, connectiQnfwith a; pracketeS I; iiixedmithfl' ILateral @displacement in 'pnefdirectiona will-dori 'fmetallicand ldielectric portions.

451* the-,compound prone located -nf-thefcavtes on 4its fporticna 33a andband-dielectric portions-34' 1 Figurer.sarespaced'jrom eachfother, whereas @1 0 33, which depends to approximately mid height ofthe cavity when the lever is at its neutral or mid-position, is preferably coaxial with the cavity and is metallic. The lower portion 34 of the prong is shown of greater diameter than the upper portion 33 and is axially eccentric thereto and of insulative or dielectric material. The ec-V centricity isyin a direction which locates the prong portion closer to the cavity Wall at the side thereof having the gap opening into the cathode cavity, that is, so the dielectric prong portion is close to andxparallel with said gap. It is Within the scope of my invention to omit the metallic portionof the prong,` and apply the dielectric portion-directly to the ring, V'or to interchange the Furthermore, as shownfin Figure '7, the dielectric portion 34e` may :'befprovided'with a longitudinal rib 35 withineithe .constricted portion of the resonant cavityswhere it ;wil1 intercept the most concentrat- 'edlregiomofmagnetic` E-lines and has a more pronounced'icapacitative effect. In this connectiorr'itiyvill::ricrwibe` understood that eccentricity ofrtheqdielectrc,portion asjshowrl in Figs. 1-4 as well as eccentricityandyrib-ofjFig. 7, situates the ldielectric in closer proximity lto y the region of highest :ca-pacity;l Sand-:presence TofA ,thev dielectric thereat has the greatestfeiect/ingloweringefthe i resonantire'quencyoithedevlce. Presencewof a 1 metallic; prong in a ,resonant cavity `tends to raise gtheioutput frequency, wher-,e asspresence, of'ladelectriclpronef.therein-tends' to lower the output;frequency-slitfneutralfpo sitiongoflthef-prongsi i,r; 1\` the cav-itieswithy appro priate distribution; oi .metaliand.dielectric output frequency is substantially Kthat .for-wh hreofa-ndjlss f.; `locatedairlfe i cavities;`- therebyfraising -:the re quency. imilarly, aising the prongs,mor

by r of :thedielectriciportions and less of; the meta .ns ci thefprpngfwili-beloat d in thefav .thercby-.lowerineftlie frequency. ysition of the metallic and dielectric portions andY outfcfathcscavites is inverse andrprogressiv S0 -that desired tuning may-'.bepbtained I Widerangefbore andzbelow @final axis, ther 0f eachiprne-towardthacavitywall yaneila Y-- ,.hcscetvvo- -fieuresx :then-prongs a constructed with longitudinally adjacent metallic and 334D, .'iheshowingsgldiiering in that 'f said metallic and dielectric portionsg33arandfx3ain f thetmetallicportion' dieserl` to' its next vcontiguous' vane, or cavity 4wall, Lfwlfiereas displacement in the opposite direction* bring's thev dielectric`4 portion'closer toits next contiguous; vane, vor cavity wall, thisfdiiierence in relation "ofrnetallic or dielectric portion to the respective vanehaving rotation of one material and the otherv side in:

direction of. opposite rotationof anothermaterial, and means connected to said meansfor rotating said prong.

- 2..`A body portion, .tuningl means 4therefor" coimprising an axially movable ringpnteans connected with and for moving said ring, 'guide legs projecting from said ring slidably mounted in said-*body portion, andacircular series sof.prongsf parallel to said legs and mountedonf said v ring andmovable therewith.

3.` An electron .discharge fdevice having `a cathode and an anode .,aroundtheocathode, said anode having cavity resonators radiating from the region around the cathode, saidl cavity resonators having substantially cylindrical portions axially parallel to the cathode, and tuning means having substantially cylindrical portions in said cavity resonators coaxial therewith and having other portions eccentric to said [cavity resonators and in closer proximity to the said region radiating from the cathode than said cylindrical portions.

4. A magnetron having an anode body formed with a circular series of cavity resonators each opening at opposite ends of the anode body, a tuning means comprising a crown having a circular series oi parallel prongs earch of which has one end portion of one material and the other end portion of another material meeting and joined substantially midway of the length of said prong, and each said prong having a length greater than that of the cavity resonator whereby ends of the said prong protrude from both ends of the cavity resonator and the joined ends of the different materials are within said resonator, and means projecting from and for moving the crown in parallelism to the prongs for changing the proportion of the different materials of said end portions directly included within the cavity resonator.

5. A magnetron having an anode body formed with a circular series of cylindrical and parallel cavity resonators each opening at opposite ends of the anode body, a tuning means comprising a crown having a circular series of parallel prongs each of which is within and parallel to a cavity resonator and of greater length than said cavity resonator to project from both ends thereof, each of said prongs having its opposite end portions of different material with the inner ends of the different material end portions joined together and within the cavity resonator, lmeans suppo-rting said crown movably and maintaining the said prongs in parallelism to the cavity resonators, and means projecting from and for moving sais `crewsito mangi-marmer proportion er the.

diierent materialsvof -s'aid end'lportions'di-rectly" included-within the cavityl resonator.

6. A magnetron 'having' ananOdebOdyfOrmed with a circular serie-s of vcylindrical and parallel cavity resonators each `opening at opposite ends of` l the :anode body; a" tuning-I means oomprising a crown having; af circular seriesv of parallel prongs resonator andofgreater length than' said cavity resonator tof proj ct from :both endsthereoffeach or said prongshaving one endl portiony of metal and its oppositeend portion' of zit-'dielectric with thefinner end-s offthe metalan'ddielectric portions -joinedtogetheriand with" the joint Within the .cavity "resonator, means supportingV saidcrownvrnovably. and maintaining the said prongs inparalle'lism to the cavityresonators; and means projecting from an'dfor moving said crown for changing theproportion of: the ivdifferent mate-` rials -of said end` portions the cavity resonatonf "7. A magnetron having ananode body formed with a circular series oflcavity. resonators' ea'ch opening at opposite ends ofl'the fanode" body, a tuning means comprising/a Icrown .having a circular series of parallel prongs eachoff-whi'ch'has one end portion of metal'and'theother* endportion of a dielectriomeeting Vandl joined substantially midway of'thelength ofif'said prong, and each said pronghavi-ngal lengthgreaterf'than that of the cavity resonatorV inf-which'vlsituated, whereby ends of said prong protrude from both end-s of the cavity resonator, and means :at one end of the anode body for moving the several prongs longitudinally thereby changing the proportion oi the metal portion and of the dielectric portion of the prongs directly included within the -cavity resonators.

8. A magnetron having an anode body formed with a circular series of cylindrical and parallel cavity resonators each opening at opposite ends of the anode body, said anode body having guide holes therein opening at one end of the same and parallel to said cavity resonators, a ring opposite one end of said anode body overlying the axial centers of said cavity resonators, prongs projecting from said ring into said cavity resonators parallel to the axes thereof and outof contact therefrom, guiding legs carried from said ring parallel to said prongs and projecting into said guide holes, and means yconnected with said ring for moving the ring in a direction longitudinally of said prongs and legs.

9. A magnetron having an anode body formed with a circular series of cylindrical and parallel cavity resonators each opening at opposite ends of the anode body, said anode body having guide holes therein opening at one end of the Same and parallel to said cavity resonators, a ring opposite one end of said anode body overlying the axial centers of said cavity resonators, prongs projecting from said ring into said cavity resonators parallel to the axes thereof and out of contact therefrom, guiding legs carried from said ring parallel to said prongs and projecting into said guide holes, means insulating said legs from the anode body, and means connected with said ring for moving the ring in a direction longitudinally of said prongs and legs.

10. A tuning means comprisingaJ ring having a circular series of prongs projecting therefrom, said prongs being parallel to each other and perpendicular to the ring, each prong comprising portions of substantially equal lengths of conducdirectly "included within tive material andof dielectric materiall andall ofthe conductive portions having like relation to the ring and all of theidielectrc portions having each the same relationas all other dielectric portions to the said ring.

11. A.. tuning means comprising a ring having a circular series of prongs projecting therefrom, said prongs being parallel to each othery and perpendicular to vthe ring, each prong compri-sing portionsrof conductive material and of dielectric material mounted end to end and with one of said portions interposed between and spacing the other portion remote from said ring.-

12. A tuning means comprising a ring having a circularV series of prongs projecting therefrom, said prongs being parallel to each other and perpendicular to the ring, each prong comprising a portion vof conductive material next said ring at one endof said portion and having the other end ci said portion remote from the ring, and each prong having a, dielectric portion endwise against the -said remote end of said portion of conductive material and therebyspacing the dielectric poru tion from the ring a `distance equal to the length of said conductive portion.

13. A tuning means comprising a, ring having a` circularseries of prongs projecting therefrom, said prongs being parallel to each other and perpendicular to the ring, a yoke extending across said ring, and guide legs projecting from said yoke inparallelism to said prongs. i

14. A tuning means comprising a. ring having a circular series ofr prongs projecting therefrom, said prongs being parallel to each other and perpendicular to the ring, a yoke extending across and at its ends beyond said ring thereby providing projecting ends for the yoke, and guide legs perpendicular to said yoke and parallelto said prongs and carried by said projecting ends of the yoke. v

15. Artuning means comprising a ring having a circular series of prongs projecting-therefrom, said prongs being parallel to each other and perpendicular to the ring, a yoke extending across the ring, guide legs projecting from said yoke in parallelism to said prongs, and insulating sleeves on said legs.

HOWARD L. STEELE, JR.

-REFERENES CITED Southworth Sept. 13, 1938 Samuel Aug. 15, 1939 Number Haeff May 21, 1946 Spencer Sept. 24, 1946 Bondley June 17, 1947 Hansen et al Oct. 21, 194.1k 

